Centrifugal machine



@ubuntu D'ec. 3l, 1929. w. H BATH CENTRIFUGAL MACHINE Filed oct, 1o,1928 Patented Dec. 31, 1929 i UNITED 'STATES PATENT OFFICE f` WILMEB H.'BATH, OF WEST CONSHOHOCKEN, PENNSYLVANIA, ASSIGNOR` T0 THE SHARPLESSPECIALTY COMPANY,` 0F PHILADELPHIA, PENNSYLVANIA, A CORPO- nArIoN 0E:DELAWARE cEN'rEIEUGAL MACHINE Application illed October 10, 1928.Serial No. 311,561. i I

This invention relates to centrifges and pertains more especially todevices forcenl trifugally separat-in liquids.

In such devicesg-.t'e separatedl liquids are discharged from` a rotatingbowl in dispersed condition into stationary 'annular chambers, the inneredges of the top and bottom walls of which are spaced slightly from theupper surface of the bowl. Rotation of the bowl causes rotation oftheair surroundingit due to surface friction betweenthe bowl and the air.The rotation of the air develops centrifugal forces therein which tendtocause a flow of air through the spaces between the bowl and the edgesof the chambers and also along the top and bottom walls of the chambers.As a result some of the liquids are caryried by the air currents out ofthe compartment into which they were discharged from the bowl. Theliquids carried out/fof one chamber may be introduced into another thereference character 10, and within this l casing is rotatably mounted abowl 11. v This bowl is provided with a head 12 having passageways 13and 14 through which the sepa'- rated liquids are discharged indispersed condition. The head is also provided with a neck 15 by meansof which the bowl 11 is supported and rotated by suitable driving means(not shown). A cover 16 surrounds the bowl 11 and is supported by thecasing 10. A second-cover 17 is supported 'from the first cover 16 andforms therewith a chamber into which liquid is discharged from the bowl1l through the passageway 13. A lid 18 is supported by the cover 17 andforms therewith a chamber into which liquids Vare discharged from thebowl 11 through the passageway 14. i

'rotation is substantially proportional to th vdiameter of the portionof the bowl in contact.` therewith. Where the rate of rotating ofthelair is greatest the air will have the greatest centrifugal force andvice versa. The centrifugal force in the casing will therefore belgreater than that in the chamber formed by the covers 16 and-17 which,in turn, will be greater than the centrifugal force developed in thechamber formed by the cover 17 and lid 18. .l

As a result there will be a tendency for air to flow from the upperchamber into the `low.- er chamber and from the latter intothe casing.There may bea How of air in or out of either spout 19 or 20 according tothe amount of air 'which passes through the annular spaces. The air incont-act with the surface of the bowl will have a greater angularvelocity than the air in contact with the top and bottom walls of thechambers. Therefore, the air in cont-act with the top and bottom' wallswill have less centrifugal force than the air midway therebetween andaccordingly the rotating air will move inwardly in a spiral directionalong such walls and move outwardly in a spiral direction intermediatethe walls. v

The currents df air thus produced by rotation of the bowl tend to carryout from the chambers some of the atomized liquid suspended in the airthereinas well as 'to carry liquid which has been deposited on thebottomand top walls of the chamberstoward the inner edges of the covers fromwhich it may drop or be blown downwardly out of the chamber by theabovede'scribed currents. As a result, liquids discharged into. one ofthe chambers may be carried out therefrom into another chamber or imothe casing of the centrifuge, thus causing either intermingling or lossof the separated liquids.

According to this invention the flow of air from the lower chamber tothe casing 10 is prevented by supporting an inverted frustoconicalcollar 21 at the inner edge of the cover 16 and providing helical vanes22 projecting from the inner face of the collar toward the bowl. Thevanes decrease in width downwardly so that the inner edge of the vanesare equally distant from the axis of the bowl. The channels formed bythe vanes of the collar are therefore of increasing cross section inupward direction. The upward` slope of these vanes is in the samedirection as the direction of rotation of the bowl 11.

These vanes have a shearing effect upon the air rotated by the bowl 11.The shearing action of the vanes produces upward flow of air in thechannels formed by the vanes and the collar. The production of theupward flow of air is assisted by the upward and outward slope of thecollar. The flow of air in the channels is therefore directed upwardlyand outwardly across the top edge of the collar. This current of airtends to carry outwardly of the chamber any liquid which may becollected on the top edge of the collar as well as the atomized liquidin the vicinity thereof. The air carried upwardly in this way isreplaced by air from the casing which is provided with an air inlet'(not shown). The current of air thus produced effectively prevents lossof liquid from the lower chamber to the casing. The upward flow of airymay be varied by variation in the dimensions of the vanes and thevariation of the inlet to the casing.

The primary effect of this invention is to prevent leakage of liquidfrom the lower chamber into the casing 10 by creating in the channels anupward pressure which counterbalances the downward pressure created byrotation of air in the casing 10. However, the upward current of airproduced according to this invention may be made sufficient to create abalance of conditionsbetween the lower and upper chambers so that thereis no current of air through the annular space connecting the twochambers. In this way. the invention has the secondary effect ofeliminating liquid leakage from the upper chamber to the lower chamber.Furthermore. if leakage in one direction is very objectionable but isunobjectionable in the other direction the upward current of air may bemade sufficient to prevent leakage in the objectionable directionalthough permitting it in the unobjectionable direction.

Although in the embodiments of the invention specifically disclosedherein, the collar 21 is supportedV b y the cover 16 and prevents lossfrom the lower chamber to the casing. it is apparent that it is withinthe contemplation of this invention that the collar be supported by thecover 17 for the purpose of preventing loss from the upper to the lowerchamber. The invention can be made use of wherever it is desired toprevent loss from a discharge chamber of a centrifugal machine.

It is, of course, understood that various structural modifications maybemade in the above disclosure without in any way departing from thespirit of the invention as defined in the appended claims.

I claim 1. In a centrifugal machine, a casing, a bowl rotatably mountedtherein. covers forming chambers for receiving liquids discharged fromsaid bowl, an inverted frust'o-conical collar carried by one of saidcovers and helical rvanes projecting from the inner face of the vanesprojecting from the inner face of the collar toward the bowl, said vaneshaving their innerI edges equi-distant from all points from the axis ofthe bowl.

4. In a centrifugal machine, a casing..a bowl rotatably mounted therein.covers forming chambers for receiving liquids discharged from said bowl,an inverted frusto-conical collar carried by one of said covers andhelical vanes projecting from the inner face of saidcollar and formingupwardly extending helical channels.

5. In a centrifugal machine, a casing, a bowl rotatably mounted therein,covers forming chambers forreceiving liquids discharged from said. bowl,an upwardly fiaring collar carried by one of said covers and means forimparting upward. velocity to air rotating in the space between thecollar and the bowl.

6. In a centrifugal machine, a casing, a bowl rotatably mounted therein.covers forming chambers for receiving liquids discharged from said bowl,an upwardly flaring collar carried by one of said covers and meanswithin said collar for causing Vupward flow of air in the space betweensaid collar and bowl. In testimony whereof, I have signed my name to\this specification: I

WILMER H. BATH.

